Water cooled cathead



s. w. WEBSTER 2,320,901 WATER COOLED CATHEAD Filed June 8, 1940 2Sheets-Sheet l June 1, 1943.

June l, 1943. s, w` WEBSTER VWATER COOLED GATHEAD 2 sneaks-sheet 2 FiledJune 8, 1940 Patented June 1, 1943 naar WATER COOLED CATHEAD Samuel W.Webster, Houston, Tex., assigner to Emsco Derrick & Equipment Company,Los Angeles, Calif., a corporation of California Application June s,1940, serial No. 339,505

3 Claims.

My invention relates in general to equipment employed in the Welldrilling art and relates more particularly to a cathead having means forcooling the same.

The device known in the well drilling industry as cathead comprises aspool ordinarily arranged for rotation at one end of the drawworks ofthe drilling rig. The purpose of this cathead spool is to apply force toa line or rope to pull the line forward or to hold the same in tension.As an example of the use of the cathead spool, the workmen on thederrick may attach a rope to an article which is to be held or movedand, extending this rope to the cathead will coil several turns of ropearound the cathead, which at the time may be in rotation. Tension isthen applied to the free end of the rope so as to tighten the coil uponthe spool so that force will be transmitted frictionally from the spoolto the rope.

In the foregoing manner the spool is employed to apply tension to therope so as to hold the rope against a reacting force or to cause therope to be spooled forward, the movement of the rope being controlled byloosening and tightening of the coil of rope around the spool so as tovary the force frictionally transmitted from the spool to the rope.Under some conditions of operation the cathead spool will heat up veryrapidly.

It is an object of my invention to provide a cathead assembly adapted tobe readily secured to existing drawworks structures, this catheadcomprising a spool chambered so as to receive a refrigerant, and meansfor passing a ysuitable refrigerant, preferably water, through thechamber of the spool.

It is an object of the invention to provide a cathead spool having anopening leading thereinto from one end of the spool, means for passingwater into the interior of the spool through the opening at the end ofthe spool, and means at the same end of the spool to receive therefrigerant which discharges from the spool after it has absorbed heat.

A further object of the invention is to provide a water cooled catheadassembly having a chambered spool and means at one end of the spool andsupported directly upon the shaft which carries the spool, for causingcirculation of Water through the chambers within the spool. An advantageof this form of my invention is that it may be readily applied to theprojecting end of any shaft of suitable diameter as a self containedunit. Y

Further objects and advantages of my invention will be brought out inthe following part of the specification.

Referring to the drawings which are for illustrative purposes only:

Fig. 1 is a fragmentary perspective View showing a portion of a rotarydrawworks with my new cathead projecting therefrom.

Fig. 2 is an enlarged cross-section taken on a plane indicated by theline 2-2 of Fig. l.

Fig. 3 is an end view of an alternative form of my invention.

Fig. 4 is a cross-section taken on a plane represented by the line 4--4of Fig. 3.

In Fig. l of the drawings I show a rotary draw- Works I0 of the enclosedtype now in general usage, this drawworks having an end Wall II, asshown in Fig. 2, through ,which a shaft I2 projects for support of acathead in a position exposed at the end of the drawworks. On theprojecting end of this shaft I2 I have shown a self contained watercooled cathead unit I3 forming one embodiment of my invention.

The cathead unit I3, as best shown in Fig. 2, comprises a cathead spoolI4 having an outer wall I5, a portion of which is cylindrical, and aninner wall or quill I6 provided with a bore I'I to receive the end ofthe shaft I2. The relative sizes of the walls I5 and I6 are such that acylindric chamber I8 is formed within the spool and in communicationwith the outer wall I5. The outer end of the chamber I8 is closed by aradial wall I9, and several webs 2li may be extended from the hub I6 tothe outer wall I5 at suitable intervals. The chamber I8 is open at oneend of the spool I4, namely, the ends of the spool I4 faced toward thewall II of the drawwor-ks, and this communication of the chamber I8 withthe exterior is accomplished through an annular opening ZI formedbetween the wall of the hub I6 and an inwardly turned lip 22 near theend of the outer wall of the spool I4.

At the inner end of the outer wall I5 of the spool I4 a flange 23 isformed, this flange having a plurality of radially outwardly projectingannular ribs 24 separated by grooves 25. lThis flange 23 extends into anopening 26 in a hollow body 21 supported between the cathead spool I4and the wall II of the drawworks. The hollow body has a circumscribingor circumambient channel 21a which is enlarged at 28 in the lowerportion of the body 21, and this lower portion of the body 2l isprovided with an outlet opening 29 to which a carry-off pipe 30 may beattached. `The body '2l is supported on the shaft I2 by bearing meanscomprising an a Y f inner race 3l, an outer race 32, and rollers 33. Theinner race 3I is conveniently formed by the projecting portion I 6a ofthe hub or quill I6, thereby making it possible to assemble the entirecathead unit before its placement on the projecting end of the shaft I2.The outer race 32 comprises a wall portion of the body 21 disposed inspaced relation to the projecting portion 3l of the quill I5 which formsthe inner bearing race. The projecting portion vII of the quill is shownbroken to indicate that its length may be varied in accordance with thespacing desired for the spool I4 from the wall II of the drawworks I0.For the extended type of cathead, the extension I6a of the quill will berelatively long and for close-coupled use of the cathead it will beshort.

The hollow body 21 has inwardly faced grooves J 34 disposed around thens 24 of the spool I4,

these grooves being arranged to readily drain into the lower` part ofthe hollowbody 21 through a notch or opening 35. A water delivery pipe3B extends through the upper wall of the hollow body 21 and on the innerend thereof has a nozzle 31 positioned so as to direct water jets 38through the opening 2| into the upper portion of the chamber I8, therebybringing this water into engagement with the outer wall I of the spoolI4 to cool the same. y

A feature of the arrangement shown in Fig. 2 is that it may be assembledas a unit prior to placement on the shaft I2. To secure the hollow body21 in operative position, a split ring 39 is secured in a groove in thequill Ita, this ring 39 constituting a grease seal which extends acrossthe end of the bearing chamber 42 in which the rollers 33 are operative.A ring 43, having an annular space 4I, 'is secured by screws 44 to therear or inner face of the hollow body 21, in a position to enclose thering 39, this ring 43 having an inwardly directed annular wall 45to lieover the outer face of the lip 4I, therey formingv a thrust bearinginterengagement between the rotating projection 3I and the stationaryhollow body 21. A feature of the invention includes also the provisionof a stop for preventing rotation of the hollow body 21, such stop meansbeing shown as tthe drain pipe 30. As shown in Fig. 2 rotation of thehub I6 relative to the shaft I2 may be accomplished in the customarymanner by means of a key 55, and to limit outward axial movement of thespool I4 on the shaft I2 I have shown an axial screw 5I which passesthrough an end plate 52 and has threaded engagement atl 53 with theshaft I2. Y

In Figs. 3 and 4 I show an alternative form of the invention wherein thecoolant disposal means, instead of comprising a hollow body 21 mountedfor rotation relative to the shaft I2, consists in a two part shell 53comprising upper and lower portions 54 and 55 secured together by boltmeans 56 and having a flange 51 whereby the shell may be secured to thewall II of the rotary drawworks by means of screws or bolts 58. Theshell 53 has a front wall 59 with an open ing 60 defined by a narrowcylindric wall 6I- which projects toward the back wall 62 ofthe shell 53and has a radial lip 63 around the inner edge thereof, thereby formingaround the wall 6I which forms the opening 50, an annular cham' nel 64.In this form of the invention the spool 65 is in general similar to thespool I4. It has an outer cylindric wall 56, a hub 61 and radial ns 68connecting the hub 61 and the -wall 66. Inside the opening 55, the.spool 65 is provided with a flange 6i! which lies along the lip 63 andhas a lip 13 in circumscribing relation to the lip 63. When the spool 65is in rotation water which flows out over the flange 69 will be throwncentrifugally therefrom, and any water which may drip from the upperportion of the lip 10 when the spool 65 is stationary, will drop intothe channel 64.

A pipe 15, for delivery of water to the device, is carried through thewall of the upper section 54, and has a nozzle 16 at the inner endthereof Vto direct water into the spaces 11 within the -outer wall 65 ofthe spool 65.

At the bottom of the lower section there is a nipple 80 to which adraintube, such as a hose 8|, may be connected. In the form of the inventionshown in Figs. 3 and 4 an end plate 90, secured in place by a screw 9|,covers the outer end of the spool 65, leaving open the inner end thereofso that the spaces 11 will communicate through the opening ofthe shell53 with the interior 4of the shell.

`I claim as my invention:

l. In a water cooled 4cathead assembly for connection to the projectingend of a shaft of a rotary drawworks, the combination of: a catheadspool unit comprising a'hub and a cylindrical outer wall spaced from andconnected to said hub, a closure member for one end of said cylindricalwall and a raised circumferential lip projecting inwardly from the innersurface of said'outer wall at a point spaced from said clo' sure member,the parts forming `a refrigerant chamber within said spool unit open atan end of said spool unit; means to receive refrigerant from'saidchamber comprising a hollow body mount-ed on said hub at said end ofsaid spool unit sothat said hub may rotate therein, said body having anopening disposed in communication `with* the open end of said chamber;means carried by said body for delivering refrigerant into said chamberthrough said open end there'-y of; and a stop for preventing rotation ofsaid hollow body as said spool unit is rotated. f 2. In a water cooledcathead assembly for con` nection to the projecting end of a shaft of arotary drawworks, the combination of: a cathead spool'unit comprising ahub, a cylindrical outer wall spaced from and connected to said hub,faclosure member for one end of said cylindrical wall and a raisedcircumferential lip projecting inwardly from the inner surface of saidouter wall at a point spaced from said end closure member, the partsforming a refrigerant chamber'within said spool unit open at an end ofsaid spool unit through a mouth of reduced diameter formed by saidinwardly directed lip; means to receive refrigerant from said chambercomprising a hollow body mounted on said hub at said end of said spoolunit sothat said hub may rotate relatively to said hollowl body, saidbody having an opening disposed in communication with the open end ofsaid chamber; and refrigerant de# livery means in'said hollow bodypositioned so as to deliver refrigerant into said'chamber of said spoolunit. l

3. In a water cooled catheadassembly forconnection to the projectingendof a shaft of a rotary drawworks, the combination of: a spool unitvhaving.- acylindrical outerV wall and a hub within said outer wall inspaced relation andconnected thereto, a closure member for one end ofsaid cylindrical wall and la raised circumferential lip projectinginwardly from the inner surface of;

said outer wall at a point spacedfromsaid end closure member, the partsforming a Water chamber within said spool unit, said hub projecting fromone end of said spool unit; a hollow body having an opening to receivesaid end of said spool unit from which said hubI projects, said bodyhaving an inner annular Wall portion lying in spaced relation to saidhub; bearing means disposed between said hub and said inner annular Wallportion of said body to permit rotation of said hub While said bodyremains non-rotative; stop means to prevent rotation of said body; Waterdelivery means carried by said body to deliver water into said chamber;and a Water outlet leading from said body.

SAMUEL W. WEBSTER.

